Federal tax for single vs. married filing separately

[v0lv0drvr]

Hi all - curious to understand this a bit more. I filled out my forms as if I were single (Turbotax prefilled from the previous year) and my liability was X. I then made adjustments to reflect my new status (marriage)  selecting married but filing separately - and my liability went up by 15-20%. That was the only change I made.

I looked at the difference and can't seem to understand this. It seems like standard deduction is the same for both single and married filing separately so curious what caused the liability to go up? I have no student loans, have a mortgage (and interest), and some stock gains. Seems straightforward enough. 

Thanks!

[KrisD15 · Accepted solution]

Difficult to say without looking at your return. 

Credits lost when filing separately include 

Earned Income Credit

Education Credits

Child and Dependent Care Credit

If you are claiming the Standard Deduction for both, the Home Mortgage Interest would not be a factor UNLESS you report that your spouse is Itemizing and you are filing separately. In that case, you would be required to itemize also, which might be less than the Standard Deduction. 

I suggest you look at the two 1040 to see where the difference is. 

Click   Tax Home

Click   Review   if necessary to get Tax Tools on the left side-bar

Click   Tax Tools   on the left side-bar (you may need to use the scroll bar for the left side-bar to see this)

Click   Tools   on the drop-down list

Click    View Tax Summary   on the Tools Center screen

When you do this,   Preview my 1040   appears on the left side-bar            

Click   Preview my 1040   on the left side-bar

TurboTax explains filing separately